Conventionally, there is known a vehicle performing an air conditioning in a vehicle interior by utilizing cooling water of an engine (internal combustion engine). For example, the Patent Reference 1 proposes a technique of activating the engine when an air conditioning demand is high even during the EV traveling (i.e., the running only by the driving power of motor with stopping the engine, hereinafter used in this meaning), and continuing the EV traveling, if during the EV traveling, when the air conditioning demand is low, in a hybrid vehicle having an air conditioning mechanism of heating the air by the cooling water. By this technique, since ON/OFF of driving the engine is determined by the degree of the air conditioning demand, it is possible to appropriately meet the air conditioning request.
As another one, in the Patent Reference 2, it is proposed to suppress that the engine is frequently driven only for charging, by setting the air conditioning ability of the air conditioner to be lower at the time when the engine is stopped, than the time when the engine is being driven.